It is generally known to provide conventional organic light-emitting diodes (OLED). OLEDs are multilayer, organic, thin film devices fabricated by vacuum evaporation techniques, with resulting current voltage characteristics similar to semiconductor diodes. Displays based on OLEDs may be used in a variety of applications such as car radios, mobile phones, digital cameras, camcorders, personal digital assistants, games, notebook personal computers, etc.
Conventional OLED displays typically include an array of picture elements or pixels deposited on a patterned substrate in a matrix of row electrodes and column electrodes. Each pixel comprises an OLED formed at the intersection of each row electrode and column electrode.
Conventional passive matrix OLED displays have a structure that is well-suited for low-cost and low-information content applications such as alphanumeric displays. To drive such known passive matrix OLED displays, electrical current is passed through selected pixels by applying a voltage to the corresponding row electrodes and column electrodes. The voltage is applied by drivers attached to each row electrode and column electrode. The resulting two-dimensional series of lights (i.e. information) is viewed on a display or panel.
An external controller circuit typically provides the necessary input power, video data signal and multiplex switches of such conventional passive matrix OLED displays. The data signal is generally supplied to the column electrodes and synchronized to the scanning of the row electrodes. When a particular row is selected, the column electrodes and the row electrodes determine which pixels are lighted. A video output is thus displayed on the panel by scanning through all the rows of electrodes successively in a “duty cycle” or frame time, typically refreshing or scanning in about 1/60 second but as fast as about 1/120 second. However, this has several disadvantages including that the row drivers of such conventional passive matrix OLED displays can only drive a relatively small array of pixels (i.e. the voltage may be applied only to a single row per scan), so a minimum duty cycle is required to produce sufficient light.
Other conventional passive matrix OLED displays have two row drivers and a second set of column drivers (i.e. on opposite sides or edges of the display). Effectively such conventional passive matrix OLED displays comprise two displays that are physically close together. However, such conventional passive matrix OLED displays have several disadvantages, including that the number of horizontal pixels is limited by the capacity of the two row drivers.
Accordingly, there is a need for a passive matrix organic light emitting diode display system that energizes multiple rows of electrodes at the same time (e.g. per duty cycle). There is also a need for an OLED display that is thin and lightweight. Yet further, there is a need for a display system having one or more of these or other advantageous features.